Ignition updates to the Unofficial FAQ

#31

In article <Xns96699C7F9EAA2tegger (AT) 207 (DOT) 14.113.17>,
"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote:

Quote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966963506AD29jyanikkuanet (AT) 129 (DOT) 250.170.86:

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote in
news:Xns9668EF412B3E6tegger (AT) 207 (DOT) 14.113.17:

Randolph <trash (AT) junkmail (DOT) com> wrote in
news:429D4577.2B7930FB (AT) junkmail (DOT) com:

The
data sheet shows the diode between emitter and collector.

So then it wouldn't make much sense to try and show it.

Randolph, I'm having trouble understanding the current path through
the transistor. I found this page:
http://nobelprize.org/physics/educational/transistor/function/thegame.
h tml

It helps me understand more, but I don't get which way the current
goes through the base electrode. I have a suspicion that my diagrams
show the current going the wrong way through the transistor.
http://www.tegger.com/hondafaq/igniter-operation/index.html

There's two current paths;the B-E path and the C-E path(main path).
Current flows the opposite direction of the emitter arrow,for both
base and collector currents.

I'm having trouble getting my mind around this.

I am aware that "flow" is _commonly_ considered to be from the positive to
negative terminals of the battery, but the electrons themselves go in the
OTHER direction.

Most materials have an electron flow, which goes from negative to
positive. I've heard that some materials can have a proton flow. Both
may exist in a vacuum.

Current flow arrows on diagrams go from positive to negative.

Bipolar transistors are current amplifiers. When a current flows
through the base-emitter diode junction, a stronger current is allowed
to flow from the collector to the emitter. The C-E junction is .2 to .4
volts when the B-E junction is saturated (~.65 V). The current gain for
a power transistor is usually 10 to 100. Darlington pairs have that
gain squared. Gains are not at all consistent so they're usually
specified as a range.

MOSFETs are tiny voltage controlled amplifiers. Absolutely zero static
current is required to turn them on or off; just the capacitance
current. Because of their infinite current gain, millions may be
paralleled on a single chip to satisfy any current load. Their voltage
gain is very low - a typical gate threshold voltage is 4V and a typical
gate saturation voltage is 10V. There's no voltage drop between the
source and drain, only resistance. High voltage capability makes each
MOSFET junction larger and dramatically increases resistance.

IGBTs are similar to bipolar transistors but with an insulated gate like
a MOSFET. They have the high voltage capacity of bipolars but need no
driving current like a MOSFET. They're very slow so they're usually
limited to controlling industrial motors. (Honda hybrid cars use them
for their motors.)

Quote:

http://www.tegger.com/hondafaq/igniter-operation/index.html
http://www.tegger.com/hondafaq/igniter-operation/badigniter.html
On these two pages, is the current flow through the transistors correctly
depicted? Nobody has answered that question yet.

#32

Kevin McMurtrie <mcmurtri (AT) dslextreme (DOT) com> wrote in
news:mcmurtri-A3D31B.22241102062005 (AT) corp-radius (DOT) supernews.com:

Quote:

In article <Xns96699C7F9EAA2tegger (AT) 207 (DOT) 14.113.17>,
"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote:

I'm having trouble getting my mind around this.

I am aware that "flow" is _commonly_ considered to be from the
positive to negative terminals of the battery, but the electrons
themselves go in the OTHER direction.

Most materials have an electron flow, which goes from negative to
positive. I've heard that some materials can have a proton flow.
Both may exist in a vacuum.

Current flow arrows on diagrams go from positive to negative.

Bipolar transistors are current amplifiers. When a current flows
through the base-emitter diode junction, a stronger current is allowed
to flow from the collector to the emitter.

So then my diagrams are correct. I assumed the base electrode to act as the
switch, turning power on and off between the collector and the emitter.

Thanks.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

#33

Kevin McMurtrie wrote:

Quote:

In article <Xns96699C7F9EAA2tegger (AT) 207 (DOT) 14.113.17>,
"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966963506AD29jyanikkuanet (AT) 129 (DOT) 250.170.86:

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote in
news:Xns9668EF412B3E6tegger (AT) 207 (DOT) 14.113.17:

Randolph <trash (AT) junkmail (DOT) com> wrote in
news:429D4577.2B7930FB (AT) junkmail (DOT) com:

The
data sheet shows the diode between emitter and collector.

So then it wouldn't make much sense to try and show it.

Randolph, I'm having trouble understanding the current path through
the transistor. I found this page:
http://nobelprize.org/physics/educational/transistor/function/thegame.
h tml

It helps me understand more, but I don't get which way the current
goes through the base electrode. I have a suspicion that my diagrams
show the current going the wrong way through the transistor.
http://www.tegger.com/hondafaq/igniter-operation/index.html

There's two current paths;the B-E path and the C-E path(main path).
Current flows the opposite direction of the emitter arrow,for both
base and collector currents.

I'm having trouble getting my mind around this.

I am aware that "flow" is _commonly_ considered to be from the positive to
negative terminals of the battery, but the electrons themselves go in the
OTHER direction.

Most materials have an electron flow, which goes from negative to
positive. I've heard that some materials can have a proton flow.

don't get no proton flow unless you're into nuclear chemistry. in
semiconductors, conduction is by way of negative electrons & positive
"holes". you /can/ have [positive] ions move in the semiconductor
lattice, but they are not a part of the primary conduction mechanism &
result in mass transport & therefore degradation of the semiconductor -
they are not a proton thing.

Quote:

Both
may exist in a vacuum.

Current flow arrows on diagrams go from positive to negative.

Bipolar transistors are current amplifiers. When a current flows
through the base-emitter diode junction, a stronger current is allowed
to flow from the collector to the emitter. The C-E junction is .2 to .4
volts when the B-E junction is saturated (~.65 V). The current gain for
a power transistor is usually 10 to 100. Darlington pairs have that
gain squared. Gains are not at all consistent so they're usually
specified as a range.

MOSFETs are tiny voltage controlled amplifiers. Absolutely zero static
current is required to turn them on or off; just the capacitance
current. Because of their infinite current gain, millions may be
paralleled on a single chip to satisfy any current load. Their voltage
gain is very low - a typical gate threshold voltage is 4V and a typical
gate saturation voltage is 10V. There's no voltage drop between the
source and drain, only resistance. High voltage capability makes each
MOSFET junction larger and dramatically increases resistance.

IGBTs are similar to bipolar transistors but with an insulated gate like
a MOSFET. They have the high voltage capacity of bipolars but need no
driving current like a MOSFET. They're very slow so they're usually
limited to controlling industrial motors. (Honda hybrid cars use them
for their motors.)

http://www.tegger.com/hondafaq/igniter-operation/index.html
http://www.tegger.com/hondafaq/igniter-operation/badigniter.html
On these two pages, is the current flow through the transistors correctly
depicted? Nobody has answered that question yet.

#34

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote in
news:Xns9669D79281ACtegger (AT) 207 (DOT) 14.113.17:

Quote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns9669BF9265BD5jyanikkuanet (AT) 129 (DOT) 250.170.83:

The electrons are what's doing the moving,and they flow from neg to
pos.

The electrons flow from POSITIVE TO NEGATIVE. The electrons go from
where they are (-) to where they're not: The "holes" (+).
http://nobelprize.org/physics/educational/transistor/function/forward.h
tml

It's the actual everyday signal that's commonly perceived to go from
negative to positive.

But we have THREE paths in a transistor ("transfer resistor"). For a
non- techie, this is non-intuitive. I do not get how TWO terminals can
have THREE paths.

think of a Y water pipe.One arm of the Y is smaller than the other.But the
total water flow thru the bottom of the Y divides and part passes thru the
left arm and part thru the right arm.You can control how much water passes
thru the right arm by adjusting the flow thru the left arm.(but the water
pipe does not have any current gain)

Quote:

Please try to understand that I am not trying to be difficult, but
that this is not at all making sense to me.

I am hoping that someone, somewhere, will post with an explanation
that makes sense to my mind. In my professional life I have taught and
trained many, many individuals, and most have had certain things that
just would not "click" until the information was presented a certain
way. I am seeking that way, and I will persist until I find it. This
is driving me crazy.

This graphic:
http://nobelprize.org/physics/educational/transistor/function/amplifica
tion .html
(all on one line; copy-and-paste as necessary)
shows the signal path from base electrode to collector.

This one:
http://nobelprize.org/physics/educational/transistor/function/pointsymb
ol.h tml
(again, all on one line)
appears to show the path from emitter to collector.

I do not get this and I am trying madly to understand. Graham W would
be able to correct me in an instant. He has been the most persnicketly
critical observer and the most productive from my point of view.
Graham, where aaaaaare you?...

Graham was the ONLY one to suggest alterations to the Main Relay
function graphics. Graham was the ONLY one to inform me of certain
HTML errors, the correction of which make it easier for browsers to
display the intended information.

Ah, but wait. I just thought of something: alt.electronics. Back
soon...

Just think of a vacuum tube;the cathode(negative terminal) is heated so it
will emit *electrons*,which are attracted to the positively charged anode
plate,thus;ELECTRON FLOW,from negative to positive.

--
Jim Yanik
jyanik
at
kua.net

#35

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966A6FCED7938jyanikkuanet (AT) 129 (DOT) 250.170.86:

Quote:

think of a Y water pipe.One arm of the Y is smaller than the other.But
the total water flow thru the bottom of the Y divides and part passes
thru the left arm and part thru the right arm.You can control how much
water passes thru the right arm by adjusting the flow thru the left
arm.(but the water pipe does not have any current gain)

So then my drawings are NOT correct. I need to show the emitter (closest to
the coil) "switched off", and not the collector (farthest from the coil).
Right? Or does it matter since the effect is the same?

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

#36

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote in
news:Xns966AD347EB6D4tegger (AT) 207 (DOT) 14.113.17:

Quote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966A6FCED7938jyanikkuanet (AT) 129 (DOT) 250.170.86:

think of a Y water pipe.One arm of the Y is smaller than the
other.But the total water flow thru the bottom of the Y divides and
part passes thru the left arm and part thru the right arm.You can
control how much water passes thru the right arm by adjusting the
flow thru the left arm.(but the water pipe does not have any current
gain)

So then my drawings are NOT correct. I need to show the emitter
(closest to the coil) "switched off", and not the collector (farthest
from the coil). Right? Or does it matter since the effect is the same?

For a NPN transistor,the collector should go to the coil,and the emitter to
ground. The other end of the coil goes to +12V.
The internal diode shunts the back EMF around the transistor to
ground,protecting the transistor.

I just looked at your schematic,and it appears correct.except that terminal
3 of the Igniter module does not go straight to the Darlington base,it goes
to the IC that controls the Darlington.You need a rectangle indicating the
control IC between the Pin 3 and the Darlington base.Pin 1(tach drive)
probably goes to the control IC,too,certainly not to ground,Pin 4.

(the emitter of the Darlington probably goes to the control IC,too,then
thru a small value resistor[<1 ohm] for current monitoring by the IC,then
to ground.)

--
Jim Yanik
jyanik
at
kua.net

#37

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote

Quote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966A6FCED7938jyanikkuanet (AT) 129 (DOT) 250.170.86:

think of a Y water pipe.One arm of the Y is smaller than the other.But
the total water flow thru the bottom of the Y divides and part passes
thru the left arm and part thru the right arm.You can control how much
water passes thru the right arm by adjusting the flow thru the left
arm.(but the water pipe does not have any current gain)

So then my drawings are NOT correct. I need to show the emitter (closest
to
the coil) "switched off", and not the collector (farthest from the coil).
Right? Or does it matter since the effect is the same?

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

The emitter is the neutral part of it, the part the collector gets switched
to.

Maybe the easiest way to think of it is as a relay, where the emitter is one
end of the winding and one of the contacts. The base is the other end of the
winding and the collector is the other normally open contact. When current
is run through the "winding" (from the base to the emitter) the collector
closes the circuit to the emitter.

There are a few technical details like polarity (the collector and base both
have to be positive with respect to the emitter) and the base resistance (so
low the current has to be limited by external resistance), but the operation
in an ignitor is just like a very fast relay. In other circuits it isn't
used as a relay, and the collector current is varied more proportionately to
the base current.

Mike

#38

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966AD818247EBjyanikkuanet (AT) 129 (DOT) 250.170.85:

Quote:

For a NPN transistor,the collector should go to the coil,and the
emitter to ground. The other end of the coil goes to +12V.
The internal diode shunts the back EMF around the transistor to
ground,protecting the transistor.

I just looked at your schematic,and it appears correct.except that
terminal 3 of the Igniter module does not go straight to the
Darlington base,it goes to the IC that controls the Darlington.You
need a rectangle indicating the control IC between the Pin 3 and the
Darlington base.Pin 1(tach drive) probably goes to the control
IC,too,certainly not to ground,Pin 4.

(the emitter of the Darlington probably goes to the control
IC,too,then thru a small value resistor[<1 ohm] for current monitoring
by the IC,then to ground.)

More information here than I've gotten yet. Thanks.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

#39

"TeGGeR®" <tegger (AT) tegger (DOT) c0m> wrote in
news:Xns966AE4D412B10tegger (AT) 207 (DOT) 14.113.17:

Quote:

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966AD818247EBjyanikkuanet (AT) 129 (DOT) 250.170.85:

For a NPN transistor,the collector should go to the coil,and the
emitter to ground. The other end of the coil goes to +12V.
The internal diode shunts the back EMF around the transistor to
ground,protecting the transistor.

I just looked at your schematic,and it appears correct.except that
terminal 3 of the Igniter module does not go straight to the
Darlington base,it goes to the IC that controls the Darlington.You
need a rectangle indicating the control IC between the Pin 3 and the
Darlington base.Pin 1(tach drive) probably goes to the control
IC,too,certainly not to ground,Pin 4.

(the emitter of the Darlington probably goes to the control
IC,too,then thru a small value resistor[<1 ohm] for current monitoring
by the IC,then to ground.)

More information here than I've gotten yet. Thanks.

Something additional I thought of after I sent the last post(sorry!);
The ECU does not ground the igniter module.It only sends a signal (to the
control IC inside the igniter)for the Darlington to ground the coil.If the
ECU were to be the ground for the igniter,that would mean that the entire
coil current(several amps) would have to travel through the long wire from
igniter to ECU,and the ECU itself would have to switch that high current to
ground,which is the purpose of the igniter.

--
Jim Yanik
jyanik
at
kua.net

#40

Jim Yanik <jyanik (AT) abuse (DOT) gov.> wrote in
news:Xns966B71542D3A0jyanikkuanet (AT) 129 (DOT) 250.170.84:

Quote:

Something additional I thought of after I sent the last post(sorry!);
The ECU does not ground the igniter module.It only sends a signal (to
the control IC inside the igniter)for the Darlington to ground the
coil.

Then how do you explain this?
http://www.tegger.com/hondafaq/misc/rov-ign.jpg
Look a the text immediately below the title.

Quote:

If the ECU were to be the ground for the igniter,that would mean
that the entire coil current(several amps) would have to travel
through the long wire from igniter to ECU,and the ECU itself would
have to switch that high current to ground,which is the purpose of the
igniter.

Then I'm still looking for a definitive answer.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/